Merge pull request TheAlgorithms#13 from ms10398/master

Added Implementation of Sieve Of Eratosthenes

Author: ms10398

Algorithms/sieveOfEratosthenes.js

@@ -0,0 +1,31 @@
+function sieveOfEratosthenes (n) {
+/*
+* Calculates prime numbers till a number n
+* :param n: Number upto which to calculate primes
+* :return: A boolean list contaning only primes
+*/
+let primes = new Array(n + 1);
+primes.fill(true); // set all as true initially
+primes[0] = primes[1] = false; // Handling case for 0 and 1
+let sqrtn = Math.ceil(Math.sqrt(n));
+for (let i = 2; i <= sqrtn; i++) {
+if (primes[i]) {
+for (let j = 2 * i; j <= n; j += i) {
+primes[j] = false;
+}
+}
+}
+return primes;
+}
+
+function main () {
+let n = 69; // number till where we wish to find primes
+let primes = sieveOfEratosthenes(n);
+for (let i = 2; i <= n; i++) {
+if (primes[i]) {
+console.log(i);
+}
+}
+}
+
+main();